Improve effect analysis of bitshifts by non Int and UInt Integers

base/int.jl

@@ -504,13 +504,16 @@ trailing_ones(x::Integer) = trailing_zeros(~x)
 >>>(x::BitInteger, y::BitUnsigned) = lshr_int(x, y)
 # signed shift counts can shift in either direction
 # note: this early during bootstrap, `>=` is not yet available
-# note: we only define Int shift counts here; the generic case is handled later
 >>(x::BitInteger, y::Int) =
     ifelse(0 <= y, x >> unsigned(y), x << unsigned(-y))
-<<(x::BitInteger, y::Int) =
-    ifelse(0 <= y, x << unsigned(y), x >> unsigned(-y))
 >>>(x::BitInteger, y::Int) =
     ifelse(0 <= y, x >>> unsigned(y), x << unsigned(-y))
+>>(x::BitInteger, y::BitSigned) =
+    ifelse(0 <= y, x >> unsigned(y), x << unsigned(-y))
+<<(x::BitInteger, y::BitSigned) =
+    ifelse(0 <= y, x << unsigned(y), x >> unsigned(-y))
+>>>(x::BitInteger, y::BitSigned) =
+    ifelse(0 <= y, x >>> unsigned(y), x << unsigned(-y))
 
 for to in BitInteger_types, from in (BitInteger_types..., Bool)
     if !(to === from)

base/operators.jl

@@ -641,9 +641,10 @@ See also [`>>`](@ref), [`>>>`](@ref), [`exp2`](@ref), [`ldexp`](@ref).
 """
 function <<(x::Integer, c::Integer)
     @inline
-    typemin(Int) <= c <= typemax(Int) && return x << (c % Int)
-    (x >= 0 || c >= 0) && return zero(x) << 0  # for type stability
-    oftype(x, -1)
+    0 <= c <= typemax(UInt) && return x << (c % UInt)
+    -c <= typemax(UInt) && return x >> (-c % UInt)
+    (x >= 0 || c >= 0) && return zero(x) << UInt(0)  # for type stability
+    return oftype(x, -1) << UInt(0)
 end
 function <<(x::Integer, c::Unsigned)
     @inline
@@ -652,7 +653,6 @@ function <<(x::Integer, c::Unsigned)
     end
     c <= typemax(UInt) ? x << (c % UInt) : zero(x) << UInt(0)
 end
-<<(x::Integer, c::Int) = c >= 0 ? x << unsigned(c) : x >> unsigned(-c)
 
 """
     >>(x, n)
@@ -689,11 +689,11 @@ function >>(x::Integer, c::Integer)
     if c isa UInt
         throw(MethodError(>>, (x, c)))
     end
-    typemin(Int) <= c <= typemax(Int) && return x >> (c % Int)
+    0 <= c <= typemax(UInt) && return x >> (c % UInt)
+    -c <= typemax(UInt) && return x << (-c % UInt)
     (x >= 0 || c < 0) && return zero(x) >> 0
     oftype(x, -1)
 end
->>(x::Integer, c::Int) = c >= 0 ? x >> unsigned(c) : x << unsigned(-c)
 
 """
     >>>(x, n)
@@ -724,7 +724,9 @@ See also [`>>`](@ref), [`<<`](@ref).
 """
 function >>>(x::Integer, c::Integer)
     @inline
-    typemin(Int) <= c <= typemax(Int) ? x >>> (c % Int) : zero(x) >>> 0
+    0 <= c <= typemax(UInt) && return x >>> (c % UInt)
+    -c <= typemax(UInt) && return x << (-c % UInt)
+    zero(x) >>> 0
 end
 function >>>(x::Integer, c::Unsigned)
     @inline
@@ -733,7 +735,6 @@ function >>>(x::Integer, c::Unsigned)
     end
     c <= typemax(UInt) ? x >>> (c % UInt) : zero(x) >>> 0
 end
->>>(x::Integer, c::Int) = c >= 0 ? x >>> unsigned(c) : x << unsigned(-c)
 
 # operator alias
 

test/int.jl

@@ -199,6 +199,11 @@ end
                 @test val >> -scount === val << ucount
             end
         end
+        for T2 in Base.BitInteger_types
+            for op in (>>, <<, >>>)
+                Core.Compiler.is_total(Base.infer_effects(op, (T1, T2)))
+            end
+        end
     end
 end